Process for carrying out coupling reactions



Patented July 5, 1949 UNITED STATES ATENT OFFICE PROCESS FOR CARRYING OUT COUPLING REACTIONS a Swiss firm No Drawing. Application April 16, 1947, Serial No. 741,934. In Switzerland April 23, 1946 1 Claim. 1

According to this invention coupling reactions are carried out in the absence of heavy metals capable of forming complexes and in the presence of a water-soluble aliphatic amine.

This new method is of general application, but is especially applicable to coupling reactions in an alkaline medium. It is principally of advantage in the case of coupling reactions which occur with difliculty. As coupling reactions which occur with difficulty there may be mentioned: The coupling of diazo-components or coupling components which are easily capable of decomposition under the reaction conditions usually required; coupling reactions with components which react slowly; coupling reactions which require a strongly alkaline medium; and coupling reactions with sparingly soluble components. Among the more especially difficult coupling reactions are those in which more than one of the above mentioned difiiculties exist simultaneously. As the difliculties above described arise especially in the case of coupling reactions leading to dyestufis capable of forming heavy metal complexes, for example, ortho:ortho'- dihydroxyazo-dyestufis, the present method is in some cases especially advantageous for the production of such metallisable dyestuiis in the metal-free state. A few examples of components in the coupling reactions of which the foregoing difficulties arise, are mentioned below. It must,

however, be recognized that the course of a coupling reaction always depends on both of the components taking part, that is to say, the components mentioned are not to be regarded as diflicult to couple in an absolute sense, but only in relation to certain combinations. As diazocomponents in this connection there may be mentioned, for example, diazotized aminoazodyestuffs, and principally diazotized aminopolyazo-dyestuffs such, for example, as diazo-compounds obtained by coupling a diazotized aminosalicyclic acid with a l-arninonaphthalene coupling in the 4-position, diazotizing the resulting aminoazo-dyestuff and also coupling it with a l-aminonaphthalene coupling in the 4-position, and further diazotizing the resulting aminodisazo-dyestufi (sluggish in reaction and easily decomposable) The present process is especially useful for conducting coupling reactions with ortho-hydroxy-diazo-compounds, principally those which are obtainable from 3:3'-dihydroxy-4:4'-diaminodiphenyl such as tetrazotized 3:3'-dihydroxy-4:4'-diaminodiphenyl (sluggish in reaction and sparingly soluble), or diazo-azo-compounds from 1 mol of tetrazotized 3:3--dihydroxy-4:4- diaminodiphenyl and 1 mol of a coupling component: (for example diazo-azo-compounds from 1 mol of tetrazotized 3:3'-dihydroxy-4:4'-diaminodiphenyl and 1 mol of a coupling component containing at least one sulfonic acid group and capable of coupling in a position vicinal to a hydroxyl group).

As coupling components in the use of which the present process is of special benefit, particularly when they are to :be coupled with the first mentioned diazo-components obtainable from 3:3- dihydroxyl:4'-diaminodiphenyl, there may be mentioned: Compounds free from sulfonic acid groups and capable of coupling in a position vicinal to a hydroxyl group, for example, hydroxyquinolines, for instance, B-hydroxyquinoline (easily oxidisable in an alkaline medium), and especially naphthalene derivatives such as amino-hydroxynaphthalenes, for example, 2- amino-7-hydroxynaphthalene (easily oxidisable in an alkaline medium), halogenated hydroxynaphthalenes, for example, 5:8-dichloro-1-hydroxynaphthalene (easily oxidisable in an alkaline medium), and principally dihydroxynaphthalenes free from further substituents, such as 113-, 2:3-, 2:5-, 2:6- or 2:7-dihydroxynaphthalene (easily oxidisable in an alkaline medium) The preparation of the diazo-compounds may be carried out in the manner usual for the components in question. In some cases it is of advantage to neutralise the diazo-solution or diazo-suspension by the addition of an agent binding acid, and, if desired, separating the diam-compound by filtration.

Among the water-soluble aliphatic amines to be added for the coupling reaction there come into consideration principally those of which the alkyl residues contain only few carbon atoms. Primary, secondary or tertiary amines may be used. Moreover, it is also possible to use mixtures of two or more amines. Especially valuable results are obtained by using water-soluble aliphatic amines which contain at least once the atomic grouping in which X represents hydrogen or the group --CI-I2--CH2, that is to say, amines which contain oxygen bound in the form of an alcohol or ether, for example, monoethanolamine, diethanolamine, triethanolamine, 'tripropanolamine or mixtures thereof, or the compound of the formula fine ether-bridge may link together two alkyl residues bound to the same nitrogen atom as, for example, in the case of morpholine (tetrahydro- 1:4-oxazine), 4-methyl-morpholine, 4-ethylmorpholine or 4-(o-hydroxy-ethyl) -morpho1ine. in otherwise difiicult, coupling. reactions the amines act as solution promoters and at the same time as relatively strong alkalies without, however, having the tendency of caustic alkalies of; furthering decomposition. Accordingly, on the one hand, the coupling reaction isfavored and, on the other, undesired side reactions are actively combated. In general relatively; small; quanti ties of the aliphatic amines s me, that; is to say one or a few mols of an aliphatic amine per diazo-group. In those cases whfirethe aliphatic amine serves principally as a soli ition, promoter; it,

is generally of advantage to use it in somewhat larger quantities. Furthermore, it is possible-.to.

add, besides the aliphatic amine to be used in H se ase advanta eously: a vely mall quantities, a, further, principally water-soluble organ -s0 v nt-.. For hisinurpose asi r n tnal. solvents are, especially suitable. As ex-.

amplc h r -m r be ent q dlpyrioine, methyl, l

n. n w a e rgexam lca bv emo ne. he;

o a o t e s by; distil ation ntr t ne by, v poration). by: d ut du n t e D 6. 13 ayher, d t n of acid: sal in out, etc;

It, is knownthat coupling reactions, can with advan a e be arriednu nw h r e nce o -h avw metals cap ble: of -forming complexes, and: that: cer a n se e uch. couplingere t o s. can be. carried; out, with. the. use of diam-compounds wh ch con a then e etala wndin ommex unionand also; an al p atic amine; in the. come pls Thus, for example; it been-recomm nded o; up e: a ia otiaede mplcn chrom u -brie ethanolamine compojund 0J3; 4-.arnino- 1 -h-ydro,xy,- ben n arbQ YIic ac ds-6.. ulfo ic. a id: w t salioyclic' acid, As compad; with this; known; nr c s aprocess of; th pr sent in tion. he. adva a faa; nsider-ably der ra se.- f: p a i n- M ov r; s. ompared; with: he; n wn; m od; r -w kin with th addit ons. Q x pyri i which s; b.. 3':Pl'.QI3Q d? -'Q nductr ne. n m r s o pl s newtions he process: f: he; r sent1invent omisiecn rally;tome preferred}. because the unpleasantness of working with. pyridin, which especially pronounced when dealin with large batches, can b ayoided.

The dyestufisobtainable by; the invention are inpart known. The-known and also the: new dyestuffs so obtainable are suitablefior example, for dyeinga very widerangeofmaterials, especially cellulose fibers, sucl rlas cotton, artifioiar silk and staple fibers of regenerated" cellulose, but can also be used for dyeing animal fibers such as wool; silkandfleathere When the dyeshuiT's contain metallisable groups they may be converted in substance, in the dyebath or on the fiber into complex metal compounds, for example, copper, chromium, iron, nickel or cobalt compounds. The conversion into such complex metal compounds, which compounds may contain a plurality or; metals in the complex, is carried out by the known methods in an acid, neutral or alkaline solution, with or without suitable additions such as salts of inorganic or organic acids,

' salts of: acids forming complexes such as tartar-ic acid or aminoacetic acid, in the presence or. absence of a diluent or suspension medium sucheas-pyridine'or glycerine, and under atmospheric on superatmospheric pressure. It is especially usefulv to produce complex metal compounds, more; particularly complex copper compounds, in substance when the corresponding metal-.free dyestuffs have too weak an aifinity and the metalliferous dyestufis are sufficiently solub e: th al), dveb th r r or many, of the complex metal compounds. produced: int. substan-c e, especially cobalt and/or nickel; compounds, can-bowed for: coloring masses or. solutions-whereof such: as, nitrocellulose lacquers, artificiahresins and spinning solutions.

When disazo-dyestufisobtained by; the present; process, containonly -few groupsimparting solubility and possess an adequate or goodafiinity for. cellulose-fiberscin the metal-free condition, they may with advantagebetreated by known general, methods on thefiber. or in, the dyebath or partially on theifiber and partiallyin the (3.376% bath, with; agents yielding; metal. Advantageuslm, ow ver, the; process of-specification No.-,

2-,le8, 59i is; usedrintwh ch first c y s and: then the treatmentwiththe-agent yielding metal; arev omi c ed;int ha mebath; As agents yield-- ing metal,there-preferably comeinto consideratiop; in this, connection those which arestable;

towards-alkaline: solutions,, such; ,as; complex cop-1 per tartrates; and, others,

The l pw na xamr esil ustrate th t on tn t ein by; w igh Example If 2 15,. par-ts of, 3 3;'-dihydr0xy-4,:4=-diaminodiphenylare, tetrazotized in the. usualv manner. The. tetrazo compound; is neutralized, separated by,-, filtration, and, introd lGedinto,asuspension of 33--. parts of 2 i,.-dihydroxynaphthalene in; 40.,parts; of, water; and lfi parts of triethanolamine. cooled. to, 2f Co The whole, is stirred,while-gradually, increasing, the.temperature. .to. 30-35 9 C. in the I course;- of, 2 hour s-guntil; the coupling; is complete;.

After; dilution with, waten, the -.precipitated dyestuff. is, separated. by, filtration, and: washed. It, is.dried:,under reduced pressure, and a. product. ai d whi h yes ellulose fibers by thee-t single bath, or. 2..-bath, after-copperingprocess. navy. blue. tints. whi,ch,.are,.fast to, washing. and; light.

Byusin .twicethe; quantity, of, triethanolaminethe .couplingproceedssomewhat,more rapidly.

Et -mo The; tetrazo compound-5. from. 2116'. parts 0f? 3 3-dihydroxy-4 4-diaminodiphenyl isprepared' in thenusual manner separated; and introduced into; a. solution of 33-t-parts of 21:6-dihydroxynaph-.. thalene in, 40 pantspfiwatenand: 20 parts. of di'-. ethanolamineiucooledto 2" G: The: whole 15;. stirred while; slowly-1 increasing: the: temperature ntil: 1001112111 13; incomplete: After dilution witlr- 76;; water; ho;-prcnipitated'adyestuff is separated by filtration and Washed. It is dried underirediieed pressure. The dyestuff hasthe same" properties as the dyestuil. obtained as described. in. Example 1. v

The same result is: obtained by using 30 parts of a technical mixture ofinoria,v di-, and triethanolamine.

Example 3 The. tetrazo compound from 21.6 parts of 3 :3"-dihydroxy-4 :4-diaminodiphenyl is prepared in the usual manner, separated; and introduced at 5-10" C; into a solution of 33 parts of 2:3"-di*- hydroxynaphthalene in 50; parts of. waterv and 20 parts .of monoethanolamine. The'whole is stirred for several hours at. room temperature until the coupling is complete. After dilution with water, filtration, and drying under reduced pressure, a dark violet-blue powder is obtained which dissolves in dilute causticsodasolution with a blue coloration and dyes cellulose fibers by thesin-gi'e bath or Z-bath aflter-eoppering process reddish blue tints which are fast to washing and light.

The separated tetrazo: compound from-121.6 parts of 3:3-dihydroxy-4:4- diaminodiphenyl is neutralized, separatedby filtration, and introduced into a solution of 22.4 parts of Z-hydroxynaphthalene-'I-sulforrieacid in: 160 parts of water and zo. parts of. potassium carbonate. The whole is stirred at -15 C. until formation of the monoazo dyestufi is complete and the tetrazo compound can no longer be detected, and the monoazo dyestuff is separated by filtration. The dyestuff paste is introduced into a solution of 16.5 parts of 2:7-aminonaphthol in 30 parts of diethanolamine. The whole is stirred while gradually raising the temperature to 30-35" C. until the coupling is complete. The dyestuff is worked up in the usual manner and dried under reduced pressure. A bluish-black powder is obtained which dyes cellulose fibers by the single bath or 2-bath after-coppering process reddish navy blue tints, which are fast to washing and light.

By using zzfi-dihydroxynaphthalene or 2:6-hydroxymethoxy-naphthalene, instead of 2:7-aminonaphthol, a similar dyestuff is obtained.

Example 5 The separated tetrazo compound from 21.6 parts of 3 3'-dihydroxy-4 4' -diaminodiphenyl obtained in the usual manner is neutralized, separated by filtration, and introduced into a solution of 22.4 parts of Z-hydroxynaphthalene-l-sul fonic acid in 160 parts of water and parts of potassium carbonate. The whole is stirred at 10-15 C. until the formation of the monoazo-dyestufi is complete and the tetrazo compound can no longer be detected, and the monoazo dyestufi is separated by filtration. The dyestufi paste is introduced into 100 parts of pyridine. A suspension of 22 parts of 5 8-dichloro-l-hydroxynaphthalene in 50 parts of water and 20 parts of diethanolamine is then added, and the whole is stirred while slowly raising the temperature to -35 C. until the cou pling is complete. The dyestuff is worked up in the usual manner and dried under reduced pressure. A blue-black powder is obtained which dissolves in water with a blue coloration and in caustic soda solution with a greenish blue coloration, and dyes cellulose fibers by the single bath or Z-bath after-coppering process pure reddish navy blue tints are test to: washing and light;

By using 2:3-dihydroxyuaphthaiene, insteadoi 5:s dicnloro-r-hydroxynapnthalene, a dyestuff is obtained which yields somewhat more reddish navy blue tints.

Ewamiile 6' The separated'tetrazo compound obtained from 21-15 parts of 3-:3 -dihydroxy-4 :l '-diaiiiinodi phenylin the usual manner is introduced into a solution of39 parts-of the monoazo dyestufi (obtained by coupling"2-aminobenzene-I-carboxylic acid with 2-amino-5-naphthol-7 sulionic acid in an. acid" medium) in 200 parts of water and 30 parts of potassium carbonate. The whole is stirred atlO-ISG. the tetrazo' compound can no longer be detected in the reaction mixture, and the resulting d lsazodyestuff is separated. The latter is introduced into a solution of 16 parts of Z-hydroxymaphthalene in parts of Water and 30 parts of diethanolamine. The whole is stirred while-gradually raising the temperature to 230 10 0.. until the coupling is complete. The: dyestuff. is' workedup in the usual manner, purified, and-dried under-reduced pressure; A dark blue powder is-iobtainedwhich dissolvesin sodium carbonate solution with agreenish' blue coloration-.andidyes cellulose fibers by the single bath or Z-bathafter coppering process clear reddish blue tints: which are fast to washing. and light.

Example 7 The separated tetrazo compound obtained from 21.6 parts of 3:3'-dihydroxy-4:4'-diaminodlphenyl in the usual manner is introduced into a suspension of 33 parts of 2:6-dihydroxynaphthalene in parts of water. 40 parts of morpholine are introduced dropwise at a temperature of 5-10 C. in the course of one hour, and the whole is stirred at room temperature until the coupling is complete. The completely precipitated dyestuif is separated by filtration, washed with warm water, and dried under reduced pressure. A blue-black powder is obtained which dissolves in caustic soda solution with a greenish blue coloration, and dyes cellulose fibers by the single bath or 2-bath after-coppering process navy blue tints which are fast to light and washing.

Example 8 31 parts of the disazo dyestufi, (obtained by diazotising 4 amino-1-hydr0xybenzene-2-carboxylic acid and coupling it with l-aminonaphthalene-7-sulfonic acid, separating the aminoazo dyestufi, again diazotising and coupling with a further molecular proportion of l-amino-naphthalene-7-sulfonic acid) are diazotised in the usual manner by the indirect method. The diazo compound is cautiously neutralized in the cold, and introduced into a solution of 8.0 parts of 8-hydroxyquinoline in 50- parts of water and 12 parts of diethanolamine. The whole is stirred at room temperature until the coupling is complete, and the resulting trisazo-dyestuff is separated in the usual manner. After drying the dyestuff and grinding it, a blue-black powder is obtained which dissolves in water with a blue coloration and dyes cellulose fibers by the single bath or 2-bath after-coppering process navy blue tints which are fast to Washing and light.

Example 9 The diazo compound produced in the usual manner from the disazo dyestufi (Obtained by diazotising 15.3 parts of 4-amino-1-hydroxy-2- benzoic acid and coupling with 2243 parts of. 1- 'alminonaphthalene-7-sulfonic acid, again diazotising and coupling with 14.3 parts of l-naphthylamine) is introduced in the form of a fine jet into an ice-cold solution of 23.9 parts of 2- amino-5naphthol-'7-sulfonic acid in 300 parts of water, and 50 parts of diethanolamine. When one half of the diazo compound has been added, a cold solution of parts of sodium carbonate in 100 parts of water is introduced dropwise, and then the remainder of the diazo suspension is added. The Whole is stirred for a few hours, then heated to 65 C., and the blue trisazo dyestuii? is precipitated with 200 parts of sodium chloride. After drying and grinding, a blue- ;black powder is obtained which dissolves in water with a blue coloration and dyes cellulose fibers by the single bath or Z-bath after-coppering process blue tints which are fast to washing and light.

Example 10 100 parts of cotton are entered at 40 G. into a dyebath containing 1.5 parts of the dyestufi obtained as described in the first paragraph of Example 5 and 3 parts of sodium carbonate in 3000 parts of water, the temperature is raised to 90-95 C., 30 parts of Glauber salt are added, and dyeing is carried on for hour at 90-95 C'. The dyebath is then cooled to 80 C., the requisite quantity of a solution of complex copper tartrate file of this patent:

8 (containing 0.3 part of copper in complex union) rendered weakly alkaline with sodium carbonate is added, and the cotton is treated for about /2 hour at -90 C. The goods are then rinsed and, if desired, soaped for a short time. The cotton is dyed a fast navy blue tint.

What we claim is:

A process for carrying out a coupling reaction in the absence of heavy metals capable of forming complexes, which comprises coupling one molecular proportion of tetrazotized 3:3- dihydroxy-4:4-diaminodiphenyl with two molecular proportions of 2:6-dihydroxynaphthalene in the presence of at least one molecular proportion of an ethanolamine,

WILLY WIDMER. HANS MAYER.

REFERENCES CITED The following referenlces are of record in the UNITED STATES PATENTS Number Name Date 1,210,751 Anderwert et a1. Jan. 2, 1917 2,424,066 Straub et al July 15, 1947 2,427,537 Straub et al Sept. 16, 1947 FOREIGN PATENTS Number Country Date 102,881 Great Britain Jan. 4, 1917 374,498 Great Britain June 13, 1932 Certificate of Correction Patent No. 2,475,265. July 5, 1949. WILLY WIDMER ET AL.

It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correctlon as follows:

Column 3, line 66, for pyridin read pyridine; column 4, line 1, for shufis read stuffs; line 35, for the Word specification read Patent;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case 1n the Patent Office.

Signed and sealed this 22nd day of November, A. D. 1949.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

